The invention relates to a nonwoven fabric, method and apparatus for producing the nonwoven fabric.
In the last twenty-five years or so the development of polymeric materials has seen a tremendous growth. Polymeric materials lend themselves to a vast number of uses and applications. One of the more significant areas in which polymeric materials have been used is in the textile industry. The melt spinning of thermoplastic synthetic materials to produce continuous filaments, staple and yarns of such materials has revolutionized the textile industry.
Although much of the growth in the use of synthetic filaments has been in the use of knitted or woven fabrics, nonwoven materials of synthetic filaments also have experienced substantial growth. There are a number of methods known today for producing nonwoven fabrics from synthetic filaments and mixtures of natural and synthetic filaments. Nonwoven fabrics find a variety of uses. A specific area in which nonwoven fabrics have gained acceptance is in the manufacture of carpets. Since nonwoven fabrics made of synthetic fibers resist deterioration caused by mildew, synthetic nonwoven fabrics are used for the backing material in carpets and such carpets are excellent for use in areas exposed to moisture, such as patios and other outdoor areas.
Nonwoven fabrics are used in many other areas as well. For example, nonwoven fabrics both fused and unfused are used as substrates in the production of various laminates and as ticking material in the furniture industry. Although nonwovens are presently used in a variety of applications as indicated above, there is still a need to improve nonwoven fabrics especially with regard to their dimensional stability and strength.
Some of the nonwoven fabrics known in the art are those produced by needling fibers together employing at least one needle loom. The surface first penetrated by the needles of the needle loom is often referred to as the "face side" of the fabric and the "face side" of the fabric generally has a much smoother surface as compared to the opposite side of the fabric which is generally referred to as the "back side" of the fabric. As used herein the terms "face side" of the fabric and "back side" of the fabric are intended to refer to the respective surfaces described above.
In a number of applications it is desirable for a needle punched nonwoven fabric to have a substantial portion of the fibers forming the face side of the fabric fused together and to have a substantial portion of the fibers forming the back side of the fabric unfused so as to form a fuzzy or nap-like surface, frequently referred to as a beard. Also it is desirable to produce a nonwoven fabric with the face side essentially fused and the back side essentially unfused and having a "beard" which has a lower elongation and/or higher ultimate strength as compared to comparable prior art fabrics.
It is an object of the present invention to produce a nonwoven fabric.
Another object of the invention is to produce a fused nonwoven fabric with improved dimensional stability and strength as compared to fused nonwoven fabrics known in the art.
Another object of the present invention is to provide a fused nonwoven fabric produced from thermoplastic staple fibers having the fibers in the back side of the fabric substantially unfused to form a "beard" and having a higher ultimate strength and/or lower elongation in comparison to other comparable nonwoven fabrics known in the art.
Other objects, aspects and advantages of the invention will be apparent after studying the specification, drawing and the appended claims.